The present embodiments relate to a magnetic resonance tomography (MRT) local coil for an MRT system.
Magnetic resonance imaging devices for examining objects or patients by magnetic resonance imaging (MRT, MRI) are described by way of example in DE10314215B4.
In MR imaging, images with a high signal-to-noise ratio (SNR) may be recorded using local coils (e.g., coils). The local coils are antenna systems that are provided in the immediate vicinity above (anterior) or below (posterior) the patient.
During an MR measurement, the excited cores induce a voltage in the individual antennae of the local coil. The induced voltage is amplified by a low-noise amplifier (e.g., LNA, preamp) and is forwarded in a wired manner to the electronic receiving device. High-field units (e.g., 1.5 T to 12 T and more) are used to improve the signal-to-noise ratio even in the case of high resolution images.
The SNR of an image is significant in many clinical MR applications. The SNR is determined by the local coil (e.g., with antenna and active amplifiers), for example, by the losses in the antenna elements themselves. Very small antennae allow a very high SNR close to the antenna. For this reason and owing to the possibility of accelerated measurement by way of k-space subsampling (e.g., parallel imaging, SENSE, GRAPPA), there is an interest in high-channel (e.g., with a large number of channels), very dense antenna arrays having individual elements that may have a completely different orientation relative to the sending field. In addition to the SNR, the simple practicability of the local coil is a feature that may be taken into account. An advantageous arrangement of local coil elements together with a workflow-optimized mechanical design are important for simultaneous optimization of SNR and workflow.
Local coils exist in many forms, often dedicated to specific regions of the body (e.g., head, heart, prostate, knee, ankle, shoulder joint).